Causes

Lead is a metal that occurs naturally in the earth's crust, but human activity — mining, burning fossil fuels and manufacturing — has caused it to become more widespread. Lead was also once a key ingredient in paint and gasoline and is still used in batteries, solder, pipes, pottery, roofing materials and some cosmetics.

Lead in paint

The use of lead-based paints for homes, children's toys and household furniture has been banned in the United States since 1978. But lead-based paint is still on walls and woodwork in many older homes and apartments. Most lead poisoning in children results from eating lead-based paint chips.

Water pipes and imported canned goods

Lead pipes, brass plumbing fixtures and copper pipes soldered with lead can release lead particles into tap water. Although lead solder in food cans is banned in the United States, it's still used in some countries.

Traditional remedies

Some cases of lead poisoning have been traced to the use of certain traditional medicines, including:

Greta or azarcon. This fine orange powder — also known as coral calcium and sea coral — is a Hispanic remedy taken for an upset stomach, constipation, diarrhea and vomiting. It's also used to soothe teething babies.

Litargirio. Also known as litharge, this peach-colored powder is used as a deodorant, especially in the Dominican Republic.

Ba-baw-san. This Chinese herbal remedy is used to treat colic pain in babies.

Ghasard. A brown powder, ghasard is used as a tonic in India.

Daw tway. A digestive aid used in Thailand, daw tway contains high levels of lead and arsenic.

Other sources of lead exposure

Lead can also sometimes be found in:

Soil. Lead particles that settle on the soil from leaded gasoline or paint can last for years. Lead-contaminated soil is still a major problem around highways and in some urban settings. Soil close to walls of older houses may contain lead.

Water. Copper plumbing soldered with lead is a source of contamination of household drinking water.

Household dust. Household dust can contain lead from lead paint chips or from contaminated soil brought in from outside.

Pottery. Glazes found on some ceramics, china and porcelain can contain lead that may leach into food.

Toys. Lead is sometimes found in toys and other products produced abroad.

Traditional cosmetics. Kohl is a traditional cosmetic, often used as eyeliner. Testing of various samples of kohl has revealed high levels of lead.

Centers for Disease Control and Prevention, et al. Lead in drinking water and human blood lead levels in the United States. MMWR. 2012;61:1. http://www.cdc.gov/mmwr/preview/mmwrhtml/su6104a1.htm?s_cid=su6104a1_w. Accessed Sept. 30, 2013.

Centers for Disease Control and Prevention, et al. Recommendations for blood lead screening of Medicaid-eligible children aged 1-5 years: An updated approach to targeting a group at high risk. MMWR. 2009;58:1. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5809a1.htm. Accessed Sept. 30, 2013.

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